Stripper device for perforating punches



June 7,1927. 7

- N. LOESEL sTnIPPsn DEVIQE won PERFORMING rlmcnzs Eiled March 23. 1925 w l H a I INVENTOR ATTORN EYS punched in the Patented June 7, 1927.

i l r 1,631,323

UNITED STATES PATENT OFFICE.

NICHOLAS LOESEL, OF RICHMOND HILL,

NEW YORK, ASSIGNOR TO AMEBICAN CAN COMPANY, OF NEVI YORK, N. Y., CORPORATION OF NEW JERSEY.

STRIPPER DEVICE FOR rnnronar ne runoims.

Application filed March 23, 1925. Serial No. 17,547. 1

My invention relates to perforating punch presses and has for its main object the provision, in such an apparatus, of means for stripping the perforating punches of the punchings removed from the blanks being operated upon in the formation of sheet metal can covers or thelike.

In a common use of mechanism of this character, a number of small holes are blank in close proximity to each other and in the past, much difficulty has been experienced as a result of the punchings adhering to the mechanism and accumulating in such manner as to interfere with the operation. This results from the fact that both the sheets themselves and the mechanism are more or less oily, and also at times from static electricity, causing the small disks or punchings to adhere closely to one another and to the mechanism, resulting in clogging up the punch mechanism and frequently causing serious injury, to the dies, or other parts. In the past it has been necessary, on this account, to stop the mechanism for removal of theaccumulated punchings of disks. Inasmuch as this has been re quired as often as once an hour, considerable loss of time has been occasioned, as well as damage to the machinery.

My invention contemplates the elimination of this difficulty by providing stripper mechanism for removing the punchings from the punches or dies upon'eachstroke of the latter so thatit will be impossible for them to accumulate and produce the results just stated. The stripper mechanism employed in punch presses generally is not suitable for perforating presses because of the small dimensions of the punches and their close proximity to one another and it is the aim of my invention to provide stripper means adapted to thepeculiar requirements of perforating press work. r

i Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

Referring to the drawings,

Figure 1 is an elevationalview of a portion of a punch press, showing the die parts partially in section;

Fig. 2. is an enlarged plan view of the lower die block, a portion thereof being broken away for clearer illustration;

Fig. 3 is a greatly enlarged sectional view of the lower d'e block and bolster plate,

showing two of the stripper washers'formed and positioned in accordance with the invention and illustrating their relation to the punches, two of which are shown inserted in (their associated openings in the die block; an,

. Fig. 4 is a perspective view of a container having a cover thereon formed by the mechanism shownin the other figures.

On said drawings, I have shown for illustrative purposes only, a'preferred form of my invention, in which the reference character 11 indicates the bedof a press upon which are mounted two vertical standards 12, supporting the operating mechanismhof the press, which includes a cross head 13, mounted in guides 14 and carrying a die member 15 adapted to cooperate with a die block 16 mounted upon a bolster plate, 17 secured to said bed 11. v

The die member 15, in the present instance, is adapted for both a drawing and a punching operation and comprises an outer shell or cage 18 adapted to act upon the blank 19 to form a peripheral flange 21 thereon, a plate 22 being secured-within the shell 18 and having a plurality of punches 23 extending downwardly therefrom and adapted to formperforations 24, of desired number and arrangement in the blank,these perforations, in the present instance, being at the corners of acan cover, indicated by the reference character 25, adapted to fit upon a rectangular can, or box, 26, as shown 1n Fig. 4 of the drawings.

Holes 27 correspondlng to are provided adapted to cooperate with said punches to perforate the blank 19 in the manner shown in Fig. 3. The arrangement, in the present instance, is such as to provide three small holesin each corner of the can cover, though it will be manifest that other number and arrangement of the punches might be provided, if desired. The particular form of the punch mechanism, it will be understood, forms no part of my invention.

, The .die block 16 beneath the'holes 27 is counter-bored, as indicated at 28, as is the bolster plate 17 and a bushing 29 is posithe punches 23,

in the die block 16 and are stripped from said punches sacrificing all of its tioned in the counter-bore engaging at the bottom a shoulder 31 in the bolster plate. A split washer 32, of resilient material, such as rubber or spring steel, is positioned in the counter-bore 28 above the bushing 29 and is slightly counter-sunk at the top, as indicated at 33, to facilitate the entrance into the washer of a perforating punch 23. The inside diameter of the bushing 29 is slightly larger than the diameter of the associated hole 27 and the counter-bore in the bolster plate 17, beneath the bushing, is of greater diameter than said interior diameter of the bushing, this part of the counter-bore being indicated by the reference character 34:. It will be understood that this construction is duplicated for each of the punches and associated holes in the die block and the operation is as follows. A blank 19, of the size and shape required for the article to be formed, in the present instance a can cover, is placed upon the top of the die block and is perforated by the descending punches 23, which move downwardly through the stripping washers 32 and into the bush ing's 29. At the same time, the edges of the blank are bent downwardly around the sides of the block 16 to form the cover fiange21. The disks 35, cut out by said punches, are carried down through the washers 32, as shown inFig. 3, said washers being slightly enlarged by this action. U on the punches being raised on the up stro e of the press, said disks, or punchings, may adhere thereto and be carried upwardly as far, as the washers 32, but inasmuch as the latter closely hug the walls of said punches and the disks have slight burrs resulting from the cutting action, said disks are removed by said washers and are prevented from being carried further upwardly by the punches.

The punchings are free to fall out of the machine through the bushings 29 and openings 34 and should they accumulate in said bushings, no harm can result, since'they will merely be moved slightly downwardly upon each stroke of the press and finally forced out by the perforating punches.

The formed covers are carried upwardly by the punches on their up stroke and are by means of a stripper plate'36 disposed within the member 18 and carried upon a rod 37 adapted-to be actuated by any suitable mechanism, not shown.-

i It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention, or p v p material advantages, the form hereinbeforedescribed being merely a preferred embodiment thereof.

I claim:

1'. In a punch press, the combination of perforating punches, a die block having openings therein into which the punches are adapted to enter after perforating a blank, and resilient stripper washers disposed in said openings and eritending around the punches and adapted to strip the punchings from said punches on the upward stroke thereof.

2,. Ina punch press, the combination of. a movable die member carrying a plurality of closely associated perforating punches, a die block having openings therein. into which the punches are adapted to enter after perforating a blank, and resilient stripper washers disposed in said openings and extending around the punches and adapted to strip the punchings froi n's'aid punches on the upward stroke thereof.

3. In a punch press, the combination of a movable die member carrying a plurality of closely associated perforating punches, a die block having openings therein into which the punches are adapted to enter after perforating a blank, andsplit stripper washers of resilient material disposed in said openings and adapted to strip the punchings from said punches on the upward stroke thereof.

4. In a punch press, the combination of a movable punch, a die block havingv an opening formed therein into which the punch is adapted to enter after perforating ablank on said'block, and a resilient washer disposed in said opening and. extending around the punches for stripping the punchings from said. punch on the upstroke thereof 5. In a punch press, the combination of a movable punch, a die block having an opening formed therein into which the punch is adapted to enter after perforating a blank on said block, and a resilient split washer disposed in said opening for strip ping the pnnchings from said punch on the up stroke thereof.

'6. In a, punch press, the combination of a movable punch, a die block having an opening formed therein into which the punch is adapted to enter after perforating a blank on said block, and a resilient split washer disposed in said .opening'for stripping the punchings from said punch on the up stroke thereof, the opening insai'd block comn' unicating witha point of discharge of the punchings. I i

7. In a punch press, the combination of a movable punch, adie block having an opening formed therein into which the punch is adapted to enter after perforating a blank on said block, a resilient washer disposed in said "opening for stripping the punchings from said punch on the up stroke thereof, and a bushing disposed beneath and supporting said Washer and having an internal diameter sufficiently greaterthan the diameter of the punch to permit the punchin gs to pass therethrough.

8. In a punch press, the combination of a movable punch, a die block having an opei'ling formed therein into which the punch is adapted to enter after perforating a blank on said block, and a resilient split washer disposed in said opening for stripping the punchings from said punch on the up stroke thereof, said washer having an opening therein of normally less diameter than said punch, said opening being slightly enlarged by passage of the punch through the washer and the washer hugging the wall of said punch on the up stroke to remove the punch therefrom.

9. In apunch press, the combination of a movable punch, a die block having an opening formed therein into whlch the punch is adapted to enter aiter perforating NICHOLAS LOESEL. 

